Friday, July 29, 2011

So for two weeks now I've been posting everything I could find on of the issue of fireballs in D&D. It was the very first wizard's ability to be detailed in the Chainmail Fantasy rules; it's one of the most powerful and distinctive spells in the D&D game; and it's one of the most consistent magics across all editions of D&D (maintaining the same basic effect throughout each, and keeping certain language all the way from Chainmail catapults through to to 3rd Edition D&D).

I'll come out and clearly say why: As I near the very end of my work on the Book of War mass-combat system for D&D, I finally got to test the high-end magic for wizards, near the end of the book. Assume that all such wizards are level 10+ (e.g., the Swords & Spells example in the last post). Then further assume that every such wizard has either a wand of fireballs or a wand of lightning bolts. This seems reasonable because: (a) if you're a wizard on the battlefield, it seems like you'd want to have such a device (e.g., they're common even in Holmes Basic D&D for levels 1-3), (b) it simplifies the number of spells we'll likely see in use, (c) it simulates the Chainmail expectation that these abilities are effectively at-will throughout a standard battle, and (d) the assumption is explicitly baked into certain editions of D&D (e.g., see 3E stock NPC rosters for wizards).

So fireballs are common, important, and very powerful. At inception, they had a limiting factor of a special targeting rule (declare target and range of shot, as befit their special "missile" class and catapult origin), but that's highly dependent on player skill (much more so than estimating a basic cavalry-charge or missile-fire range), something that really only works in the context of miniatures on an open, un-gridded playing surface. And even then, perhaps only if our targets are masses of possibly hundreds of figures per unit. And so perhaps that's why they were given such large areas-of-effect, to possibly compensate for this targeting challenge. (?)

The targeting language was explicitly copied forward throughout every edition of D&D, but the assumptions no longer really worked. Play without miniatures? Then the mechanic is nonsensical. Play on a grid? Then the mechanic is trivial. Play D&D with just a few miniatures per side? Then targeting is extremely difficult (even with minis on an open table). Use the space-expanding rule as a counter-balancing measure? Then it's extremely complicated and almost too dangerous to use the spell underground.

My guess is that almost nobody actually enforced that targeting rule in the AD&D era and beyond. It's so unlike how any other spells are targeted that you'd easily forget about it. And the rulebook language got "submerged" by rewriting it in the in-game character's perspective ("The magic-user points his or her finger and speaks the range (distance and height) at which the fireball is to burst." [AD&D PHB]), so it's no longer clear if the player actually needs to do the same.

What I found in my game is that if the wizard can just drop fireballs anywhere they want with pinpoint accuracy, then they can continually target enemy heroes with every shot and quickly eliminate them from the game (notice how that never happened in Gygax's example of play in Swords & Spells, even though other spells like hold person targeted enemy heroes without difficulty). On the other hand, if we enforce then age-old "declare range" rule, then it's almost overwhelmingly difficult to hit anything (as usual, for mobile targets in the open field) unless you've got hundreds of figures per unit, or are somehow cheating by pre-measuring. (And I confess that the last time I played, in desperation, I resorted to comparing to known grain marks on the table surface -- although I still lost.) And in that case, the canonical fireball becomes basically useless.

So, what's the best thing to expect from the game now? How are most people using fireballs; are they balanced and a reasonable thing to use; and how do they fit in with the traditions of classic D&D? I ask this both for Book of War and also a potential Book of Spells update. Here's a brainstorm of every mechanic I could think of over the past few weeks:

Wednesday, July 27, 2011

Fireball is such a signature D&D spell that it probably deserves more than a single post in its honor (as from last time). Here, let me add some personal observations on the topic (which admittedly evolve a bit over time):

To begin with, I'm not enormously fond of the attack spells fireball or lightning bolt on their face. First, they may not be at the right level; perhaps they should have been converted from Chainmail (where they had no "complexity" rating) at a level higher than 3rd. Second, I think they're generally too powerful, especially with their large and devastating area-of-effect which is a legacy of the OD&D Vol-3 1"=10 feet scale (which probably should have been 1"=5 feet). Third, I think that their showy, flashy, loud nature is out-of-place with more traditional fantasy depictions of magic-using wizards, and that these indispensably powerful spells are the vanguard in what grates lots of people about the D&D magic not feeling right to them (in fact, they almost accomplish that deed alone). Again, a lot of this is the legacy of their being introduced in Chainmail entirely outside the rest of the system for "spells", and simply being a fantasy replacement for the catapults & cannons that were available in the historical side of that game (and which may themselves have been overpowered in the first place).

Two exceptions I can think of to that last point -- Near the end of the Conan story "The Scarlet Citadel" (the second-ever published Conan story by Robert E. Howard) the warlord barbarian faces off against an enemy sorcerer:

Old Tsotha rose and faced his pursuer, his eyes those of a maddened serpent, his face an inhuman mask. In each hand he held something that shimmered, and Conan knew he held death there... "Keep off" screamed Tsotha like a blood-mad jackal. "I'll blast the flesh from your bones!"... Conan rushed, sword gleaming, eyes slits of wariness. Tsotha's right hand came back and forward, and the king ducked quickly. Something passed by his helmeted head and exploded behind him, searing the very sands with a flash of hellish fire. Before Tsotha could toss the globe in his left hand, Conan's sword sheared through his lean neck. ["The Scarlet Citadel"]

So here we see a very fireball-like effect, although the ability is arguably really a mundane chemical one, and the threat is much more limited: only so far as the wielder can physically throw it. There is also a similar scene in the story "The Black Colossus", in which a wizard rides by chariot across the front of an opposing army, spilling a "thin powdery line" from a large golden receptacle that then explodes very much like a wall of fire. (I feel like later Conan stories lost this intriguing ambiguity in regard to the powers of those so-called wizards).

And the other fantasy example I can think of is "Tim the Enchanter", played by John Cleese in Monty Python and the Holy Grail (1975). In fact, it's rather remarkable what a perfect resemblance Tim's powers have to the D&D fireball spell (including great range and area). But otherwise, the piece is obviously a comical spoof of what a wizard normally looks like.

Okay, so back to the main topic -- Granted that fireballs are so enormously powerful, we might look for ways to reign them in a bit. Like, we might consider strictly enforcing the "call range and height" rule that's actually in the rules everywhere from Chainmail to 3E, so that the positioning of the shot is less predictable. But use-cases for that will be (a) miniatures on an open table, which I think are both rare and really hard to succeed at (esp. with a few scattered figures instead of Chainmail/Swords & Spells expected hundreds of figures en masse), (b) a gridded battlemap, where it's trivial to land the shot (or at least infeasible to prevent pre-measuring), or (c) no miniatures at all, where you're really at the mercy of whether the DM is telling you the exact enemy distance or not. And perhaps more importantly, it's possibly an irritation that this rule is so different from how targeting works for any other spell in the D&D rule system. (Note: I kept the rule for fireball & lightning bolt in my Book of Spells product, for consistency.) I think some other DM's will at times call for to-hit rolls, Intelligence checks, grenade-like bounces (see CM "Fire optional") or the like to accurately place the fireball, but clearly this is off-book usage.

Let's look at another source. Gygax's Swords & Spells rulebook (mass combat for OD&D: basically Chainmail formation & movement wedded to average-damage computations for all combat and magic; thus, a very calculator-heavy game to play) has an extended "Example of Game Play" at the end of the book, which I think is the only example of D&D play anywhere in which fireballs actually get used. In it, an army led by a good Wizard faces off against forces led by an Evil High Priest [EHP]. Picking up the action around turn 4:

... the Necromancer tosses a fire ball into the midst of the elves. No morale checks are necessary, despite a fair number of hits being scored on both units now... At the beginning of the following turn the EHP is surprised to see a fire ball crashing into the ranks of the hobgoblins, for the deceptive fellow [the Wizard] has entirely ignored the cloud kill... The hobgoblins take over 20% casualties, but their morale remains good... At end-turn the necromancer hurls a fire ball at the treants, and when the EHP reconsiders, he throws a hold person at the Wizard. This attack is answered by a fire ball from the Wizard which strikes the EHP's own guard. [S&S, p. 38]

Before I analyze this, a few things from earlier in the rulebook. On spell casting:

Spells/magical attacks must be designated as regards range and aiming point, when applicable. [S&S, p. 11]

So in principle that same old targeting rule is still on the books here, and apparently generalized to any kind of spell or magical attack. But look back to the "Example of Play". At no point is anyone pictured as declaring a particular range for a shot -- either for fireballs or any other spell utilized. (Well, almost: On the second turn, "Wizard casts continual light spell to maximum range in air straight toward enemy center.") Notice that none of the fireballs or other spells ever miss their targets. But I'm left wondering: If the Wizard could hit the EHP's ogre guards with a fireball, then why didn't he just drop it on the EHP himself (standing just a single figure-width back)? Or, why didn't he throw one on top of the evil Necromancer who's standing alone in the open in this scenario? Seems like either of those plays would have helped to end the battle much more quickly, but for some reason things didn't work that way.

One other thing about magical attacks like these: Swords & Spells has a special rule for area-effect damage which seems intended to limit the overall effect of fireballs in particular (as usual, the example for the section is indeed our trademark fireball). Recall that in Chainmail a fireball would just kill all the figures it touched (with some high-level exceptions given a save); by the book in any form of D&D, it does full damage to everyone in a 40' diameter underground (say 20 points minimum to each of around 22+ figures man-to-man). Actually, it's even worse in S&S, because Gygax hadn't yet invented the area-stays-in-feet-outdoors rule, so the outside area for fireball is still listed at a full 4" diameter (at 1"=10 yards scale; 40 yard diameter; over 11,000 square feet; 22 figs x 10 men/fig = 220 men potentially affected?), and likewise for all the other spells [S&S, p. 12-15] Anyway, here's the special rule for assessing damage:

Spell Damage: The number of points of damage inflicted by attack spells is basically that indicated by the D&D system, i.e., one 6-sided die of damage for each level the spell caster has attained, using wands as six dice and staves as eight dice when damage is thus necessary to determine. Damage dice remain at 6-sided, so the average damage per level is 3.5 points.

When spell damage is to be determined the number of scale creatures represented by the figure(s) affected by the spell/magic is important. If the figure represents but a single creature (of unusual nature, of course) then the possible maximum damage is simply the number of levels of the spell/magic times 3.5. However, if the figure represents ten scale creatures, the base damage possible is:

level × 3.5 × 5

Thus, a fire ball cast into the midst of attacking orcs will do the greater amount of damage, modified by the possibility of the orcs making their saving throw or throws if more than one figure of orcs are in the area of the fire ball. Assuming that there is a unit of 10 orc figures representing 100 scale orcs, and that a 10th level magic-user casts a fire ball into their midst which affects 8 of the 10 figures, a maximum damage of 3.5 × 10 = 35 × 5 = 165 possible damage points. Each of the 8 orc figures would then be diced for to see if they received the full blast, and those that save take 1/16th of the total damage, those which fail take 1/8th, i.e., 11 points or 21 points respectively. Note that all remainders are rounded UP to the nearest whole.

If but a single figure of orcs were caught in such a blast they would be killed regardless of saving throw, but in the 10-figure example above, the affected figures would all have points of damage recorded against their unit, and for every 45 points of damage scored upon them a figure would be removed. Remember, a side record of damage taken by each figure or unit must be kept, so that casualties can be extracted when appropriate. [S&S, p. 12]

So, I find that to be an interesting passage (excusing the poorly-written math equation). It seems to be a novel new rule for affecting a mass of creatures, rather arbitrarily added to the whole, and I can't quite see the rationale for it. Gygax calls it a "greater amount of damage", but the truth is, it's a reduced amount of damage from we'd normally expect -- which is to say, the full fireball damage applied to each individual creature separately. In the example above, we would normally expect a total of level × 3.5 × 80 = 2,800 points of damage (if no one made a saving throw). So basically this rule sets a hard maximum on area damage, which then gets divided up amongst all the creatures involved (in the example, about 1/20th what we'd get from directly applying the fireball to each creature individually).

So, why this rule? Is it simply a flat-out nerfing of the fireball spell which Gygax could see was overly powerful on the battlefield? Why was it never seen again in any later version of D&D? Is it superseded by the later rule in AD&D which limits area of effect to a scale of feet outdoors (i.e., 1/3 the dimension here, so 1/9 the area and number effected?) Or is it an attempt to simulate the shielding and cover effect which might be granted from scores of bodies all packed together? And is that special targeting rule really still in effect here?

Monday, July 25, 2011

It got scorching-hot around here this weekend, so I figured it was the best possible time to investigate that iconic D&D spell, fireball. We laid the groundwork for this a week ago, since the true roots of the spell are in the Chainmail mechanics for catapult fire. Remember that? Good, then off we go...

Chainmail Fantasy

Missiles: A Wizard can throw either of two types of missile (select which before play begins). A fire ball, equal in hit area to the large catapult hit area, or a lightning bolt, 3/4" wide by 6" long, with an attack value equal to a heavy field gun, are the two missile types employed. These missiles will destroy any men or creatures which are struck by them, with certain exceptions noted below. Both types of missiles can be thrown up to 24", direct or indirect fire, with range being called before the hit pattern is placed. The center of the fire ball is placed down at the number of inches called. The head of the lightning bolt is placed at the number of inches called, so that its body extends 6" behind it in a straight line from the Wizard who threw it. [CM, p. 31]

Note that these attack spells (fireball and lightning bolt) are in a separate "Missiles" class, distinct from those powers called "Spells" (16 of which are listed in a following section). The "missiles" are apparently usable at will; they have no complexity rating; they are not subject to the "number of spells" limitation; and they have their own unique range and targeting mechanism.

The range-calling mechanic, which we saw previously for the catapult rules (and I would argue is at least partly troublesome), is again explicit here: "range being called before the hit pattern is placed". Based on context and what comes afterward, I think that this is not the two-axis (x,y) range method for catapults, but rather the point-at-the-target-and-call-a-range rule, the same as for cannons. In any event, the fireball eliminates almost everything in the game within its 3½" diameter blast area, excepting only the powerful types with saves shown above (again, much like the referenced heavy catapult). Also, Wizards themselves save on a 7 or better, modified by difference in rank between the magic-users (higher up on CM p. 31).

A final observation is that the fireball rule has almost precisely the same effect as the base heavy catapult rule; whereas the lightning bolt mechanic is somewhat more loosely inspired by the heavy field gun (lacking the multiple-bouncing-cannonball death zones). Are the "Fire Optional" rules for variation of the shot ranges applicable here? I don't know. I suppose it could be used by some DMs if they wanted. (I've tried to do so in the past, especially for ship-to-ship combat.)

Original D&D

Fire Ball: A missile which springs from the finger of the Magic-User. It explodes with a burst radius of 2" (slightly larger than specified in CHAINMAIL). In a confined space the Fire Ball will generally conform to the shape of the space (elongate or whatever). The damage caused by the missile will be in proportion to the level of its user. A 6th level Magic-User throws a 6-die missile, a 7th a 7-die missile, and so on. (Note that Fire Balls from Scrolls (see Volume II) and Wand [sic] are 6-die missiles and those from Staves are 8-die missiles. Duration: 1 turn. Range: 24" [OD&D Vol-1, p. 25]

So in OD&D we see a fireball much like we're familiar with in any version of D&D. The missile attack has now been absorbed into the larger overall spell system, and given 3rd-level status (just like lightning bolt; all the other spells in Chainmail had their "complexity" convert directly to "level"). The text explicitly refers back to the Chainmail rule, so I think we must assume that targeting of the spell is still officially done by range-declaration of the shot (and see later editions, too). If so, then fireball and lightning bolt both share a unique targeting mechanic unlike any other spell in the rules (a legacy of their being in a different non-"Spell" class in Chainmail). See also: "Special Ability functions are generally as indicated in CHAINMAIL where not contradictory to the information stated hereinafter" [Vol-2, p. 5].

We also see the first appearance of the "conform to the shape of the space" language for fireball. There is additional information on this point in the DM's booklet:

While some referees allow Fire Balls and Lightning Bolts to be hurled in confined spaces, blasting sections of stone equal to the remainder of their normal shape, it is suggested that the confined space cause these missiles to rebound toward the sender, i.e., a Lightning bolt thrown down a corridor 40 feet long will rebound so as to reach its stated length of 6" (60 feet underground), and this will mean the sender is struck by his own missile. It may also be compromised, allowing say two feet of stone wall to be destroyed (allowing one foot of stone destroyed for every ten feet the space is short of full distance) and rebounding the missile one-half the distance short. [OD&D Vol-3, p. 9]

Okay, so if some early DM's were treating fireballs as demolition dynamite, and incinerating stone 20 feet deep with every shot, then that's pretty silly and needs to be cracked down on. But this may possibly be one of Gygax's "cure as bad as the disease" moments, as the response has already caused a whole bunch of math extrapolations to pop up during play that may not even be consistent ("one foot of stone destroyed for every ten feet the space is short of full distance... rebounding the missile one-half" yadda yadda). I mean, an alternative -- maybe the lightning bolt in the example just grounds to the earth when it hits a solid wall? Maybe?

Holmes D&D

Holmes spells stop at 2nd level; a list of 3rd level spell names is given, but without any descriptions or effects ("They are listed above to give some idea of the range of magical possibilities", Holmes p. 16). So no fireball, right? Ah, but check the magic item section:

Wand of Fire Balls -- On activation, the wand produces a fire ball which will travel any distance, up to 240 feet, desired by the user and then explode with a burst radius of 20 feet, doing 6 dice of damage to anyone within range who fails their saving throw (half damage if saving throw is made). Fire ball blasts in confined spaces generally conform to the shape of the space (so watch out!) [Holmes, p. 38]

So that's basically the same as the OD&D item (although the text there is simply, "A Wand which projects a Fire Ball exactly like the spell of that name."; Vol-2, p. 34). The blast-conforming language is again highlighted. The same targeting mechanic is obliquely described: "any distance... desired by the user".

Explanation/Description: A fireball is an explosive burst of flame, which detonates with a low roar, and delivers damage proportionate to the level of the magic-user who cast it, i.e. 1 six-sided die (d6) for each level of experience of the spell caster. Exception: Magic fireball wands deliver 6 die fireballs (6d6), magic staves with this capability deliver 8 die fireballs, and scroll spells of this type deliver a fireball of from 5 to 10 dice (d6 + 4) of damage. The burst of the fireball does not expend a considerable amount of pressure, and the burst will generally conform to the shape of the area in which it occurs, thus covering an area equal to its normal spherical volume. [The area which is covered by the fireball is a total volume of roughly 33,000 cubic feet (or yards)]. Besides causing damage to creatures, the fireball ignites all combustible materials within its burst radius, and the heat of the fireball will melt soft metals such as gold, copper, silver, etc. Items exposed to the spell's effects must be rolled for to determine if they are affected. Items with a creature which makes its saving throw are considered as unaffected. The magic-user points his or her finger and speaks the range (distance and height) at which the fireball is to burst. A streak flashes from the pointing digit and, unless it impacts upon a material body prior to attaining the prescribed range, flowers into the fireball. If creatures fail their saving throws, they all take full hit point damage from the blast. Those who make saving throws manage to dodge, fall flat or roll aside, taking ½ the full hit point damage - each and every one within the blast area. The material component of this spell is a tiny ball composed of bat guano and sulphur. [1E PHB, p. 73]

Again, mostly the same spell -- area, damage, saving throw, etc. are all unchanged. As usual for AD&D, you now have components, casting times, variable range based on caster level, and generally a lot more verbiage (note that a gunpowder-like material component is at the end of the text, but no "M" in the header). The spelling has changed; for the first time now it's "Fireball" as a single word (no space, and as I've written it myself throughout this post).

The "space conforming" rule that appeared in OD&D (in response to those who thought it should blow up stone barriers) has grown in size and complexity; a specific volume is given, implying that you should be calculating the volume of areas in your dungeon and applying this space-filling effect to them. (After years of applying this, let me offer a heartfelt mathematician's "Aaaarrgghh!!!"). Also you get an extended comment on the fireball's actual temperature and effect on metallic treasure types (melting them).

Note #1: Although material items have saving throw rules in both OD&D and the AD&D DMG, there's a special exception given in the middle here: "Items with a creature which makes its saving throw are considered as unaffected." Now, while this is the only place that such a rule appears in 1E, it's a continuation of a more general rule from OD&D ("For the sake of simplicity it is generally easier to assume they [magical items] survive unharmed if their wearer/user is not killed (exception, Helms)"; OD&D Vol-2, p. 38), and it was re-established in general for 3E (such as on 3E PHB p. 150).

Note #2: The specific targeting mechanic is still included, although it is now described from the perspective of the in-game character. "The magic-user points his or her finger and speaks the range (distance and height) at which the fireball is to burst." So with this we see a continuation of the special targeting rule that has run in common through Chainmail catapults, Fantasy fireballs, Holmes wands, and also Advanced D&D.

A fireball is an explosive burst of flame, which detonates with a low roar and delivers damage proportional to the level of the wizard who cast it--1d6 points of damage for each level of experience of the spellcaster (up to a maximum of 10d6). The burst of the fireball creates little pressure and generally conforms to the shape of the area in which it occurs. The fireball fills an area equal to its normal spherical volume (roughly 33,000 cubic feet--thirty-three 10-foot × 10-foot × 10-foot cubes). Besides causing damage to creatures, the fireball ignites all combustible materials within its burst radius, and the heat of the fireball melts soft metals such as gold, copper, silver, etc. Exposed items require saving throws vs. magical fire to determine if they are affected, but items in the possession of a creature that rolls a successful saving throw are unaffected by the fireball.

The wizard points his finger and speaks the range (distance and height) at which the fireball is to burst. A streak flashes from the pointing digit and, unless it impacts upon a material body or solid barrier prior to attaining the prescribed range, blossoms into the fireball (an early impact results in an early detonation). Creatures failing their saving throws each suffer full damage from the blast. Those who roll successful saving throws manage to dodge, fall flat, or roll aside, each receiving half damage (the DM rolls the damage and each affected creature suffers either full damage or half damage [round fractions down], depending on whether the creature saved or not).

The material component of this spell is a tiny ball of bat guano and sulphur. [2E PHB, Appendix 3]

In general, that's pretty much an exact copy-and-paste from 1E. The range/area units have been converted from scale "inches" to yards and feet. The "M" has been correctly added to the components header. And the special targeting rule is still there (the wizard speaks "distance and height" for the shot). One big change from a short piece of text: Damage is now capped at 10d6 maximum.

And there are two contextual factors in 2E which have also possibly changed the spell: First, in 1E the range in "inches" represented a sliding scale (tens of feet in the underground, tens of yards outdoors); but in 2E there seems to be no such context-switch to range, so yards apply even in the dungeon, effectively tripling the underground range (while movement in 2E switches between yards/feet, I can't find any rule to switch bow-fire or spell ranges; although perhaps I'm missing something). Edit: Or at least, that's how it would be if the spell's range formula was converted to 100+10/level yards; but what we see here is instead 10+10/level yards (a very odd conversion that I initially overlooked), which is greatly reduced outdoors at least. Indoors, it's still an increase of some degree: e.g., at 5th level 1E 150' vs. 2E 60 yds=180' (a small increase), or at 15th level 1E 250' vs. 2E 160 yds=480 ft (approximately doubling). Thanks to commentator faoladh for drawing my attention to this point.

And second, while the targeting language in the spell has been maintained, a specific example in the "Casting Spells" section of the same book seems to directly contradict it: "If the spell is targeted on a person, place, or thing, the caster must be able to see the target. It is not enough to cast a fireball 150 feet ahead into the darkness; the caster must be able to see the point of explosion and the intervening distance" [2E PHB, Ch. 7] I suspect that while the range-declaring language has been maintained throughout every edition to this point, it has now become somewhat "submerged" by the in-character point-of-view, and this external passage probably reflects the more common usage at the time (and thereby homogenized with other spells).

This spell creates a missile of fire that bursts into a ball of fire with a 40' diameter (20' radius) where it strikes a target. The fireball will cause 1d6 points of damage per level of the caster to every creature in the area of effect.

Each victim may make a saving throw vs. spells; if successful, the spell will only do half damage. For example, a fireball cast by a 6th level spellcaster will burst for 6d6 (6-36) points of damage; characters who make their saving throw vs. spell will take only half of the damage rolled on the dice. [RC, p. 48]

Figured I'd check in here on the 1990 Allston Rules Cyclopedia product, representing the culmination of the whole Moldvay (B/X)/Mentzer (BXCMI) product line. Basically, we have the same effect, although the detailed complications have been edited down quite a bit. The spelling is as in AD&D (one word). The space-conforming rule, the melting-metals rule, and also the special range-declaration targeting rule have now all disappeared. Range is still the fixed 240 feet in the dungeon you'd get from OD&D or Holmes. Attack-spell damage is more generally capped at 20 dice in these rules [RC, p. 32]

A fireball spell is a burst of flame that detonates with a low roar and deals 1d6 points of fire damage per caster level (maximum 10d6) to all creatures within the area. Unattended objects also take this damage. The explosion creates almost no pressure.

The character determines the range (distance and height) at which the fireball is to burst. A glowing, pea-sized bead streaks from the character and, unless it impacts upon a material body or solid barrier prior to attaining the prescribed range, blossoms into the fireball at that point (an early impact results in an early detonation). If the character attempts to send the bead through a narrow passage, such as through an arrow slit, the character must "hit" the opening with a ranged touch attack, or else the bead strikes the barrier and detonates prematurely.

The fireball sets fire to combustibles and damages objects in the area. It can melt metals with a low melting point, such as lead, gold, copper, silver, or bronze. If the damage caused to an interposing barrier shatters or breaks through it, the fireball may continue beyond the barrier if the area permits; otherwise it stops at the barrier just as any other spell effect does. [3E SRD]

This is still pretty much the same thing you'd see throughout the AD&D line, and most of the same language has been maintained. From 2E, it retains the 10d6 maximum cap. The metal-melting rule is still there. And so is that special targeting language (along with a "bead" physically flying through the air before the magic takes effect) -- a legacy carried all the way forward from Chainmail catapults!

One thing we've discarded is the weird 2E range scaling, looking back to 1E's 100'+10'/level underground, and then multiplying that by a factor of 4. So that's now a massive increase in the useful range of the spell, although it's in line with most other spells that matriculated through 2E and got boosted by with the fixed-to-yards scale there.

What else is not there is the space-expanding rule, and this is what is being highlighted with the language, "The explosion creates almost no pressure"; so the dungeon-volume-calculations have been streamlined out of the picture. But, to balance the scales of yin-yang, what's been added back is the contextual notion of a "spread" area-of-effect as seen here:

Spread: Some effects spread out from a point of origin to a distance described in the spell. The effect can extend around corners and into areas that the character can't see. Figure distance by actual distance traveled, taking into account turns the spell effect takes. The character must designate the point of origin for such an effect but need not have line of effect to all portions of the effect. [3E SRD]

See the image to the right for more detail on this rule (fireball example from 3E PHB, p. 204). Note how the area in the top-left corner gets "stunted" because the distance has to be measured around the corner of the open doorway there. I never saw this rule actually get assessed in practice this way, nor would I want to do so.

Finally, something else that was added to the spell description (at the end of the second paragraph above) is a mechanic to try and restrict shooting fireballs through arrow slits. However, I found that in practice that this was not very much of an effective restriction in 3E (motionless target ACs are very low, and fireball-casting wizard attack levels with Dexterity bonus quite high, which along with a lack of any ranged penalties for the spell, made for an almost trivially easy to-hit requirement).

Friday, July 22, 2011

As we saw previously, there's a marginally-interesting optional rule at the end of the catapult rules for Chainmail. It says:

Fire Optional: Roll two different colored dice. One color is for an overshoot and the other is for an under-shoot. To decide which number of use you take the higher of the two. Miss is in inches, shown by dice spots. If they tie then the rock lands at the specified range. This method is simple but effective. [CM, p. 12-13]

Recall that both fireballs and giant rock-throwing refer back to these catapult rules for their resolution (throughout both the Chainmail Fantasy Supplement and Original Dungeons & Dragons Vol 1-3). For example, this same variation rule pops up again for the giants in Holmes blue-book D&D:

Giants can throw rocks like a catapult, range 200 feet with a 20 foot hit area. Each rock does 2 dice of damage to anything it hits. A giant can throw one rock every 5 melee rounds.

There are several ways to calculate catapult (giant) fire. This one is adapted from CHAINMAIL. If figures are being used on a table, the giant estimates the range to his target and throws. The actual distance is then measured. Two six-sided dice of different colors are then rolled. One color is an overshoot and the other an undershoot. To decide which number to use, take the greater. The miss is in inches, shown by the die spots. If they tie the rock lands at the specified range. Anything within 2 inches of the impact is hit. If figures are not used, treat the thrown rock as an arrow or other missile on the combat table. [Holmes D&D, p. 26]

I'll have more to say about the overall giant-throwing rules in the future, but I'll stick to my brief, main point for today -- That variation rule is crazy-ass broken! If you roll two dice for over/under variance and take the "higher" (in both versions above) then that's biased towards being as far away from your target as possible. As one example, notice that it's impossible to land exactly 1 inch away -- a (1,1) tie lands on the bulls-eye, but otherwise (1,x), lands on whatever that other number is (x>1). Here's a histogram of all the possible results:

Have you ever seen a probability distribution look like that? No, that's just plain nuts. So my guess is there was a typo and the word "higher" should properly be replaced with "lower". (Or the original writer was just in a rush and didn't properly think it through. Or they actually played that way and didn't realize how batshit crazy it was.) Here's what the probability distribution looks like if you replace the word "higher" with "lower":

Ah, that's more like it. That's what you'd call a "triangular" distribution, with the maximum probability mass at the target (central distance x=0), and sloping off evenly to each side. Basically each of the tails have been inverted; it's now quite likely to land 1" off the target (in fact, the most likely absolute distance), and it's impossible to be as far as 6" away (maximum 5"). Note also that this is exactly equivalent to: roll 2d6, and every point away from 7 is the distance from your target (over or under). And if you added more dice to this model (like roll 3d6, vary by points away from 10 or 11, etc.), then the the histogram would look more like a properly bell-shaped curve; the limiting distribution being, as is the case in any partially-sane universe: the Normal Curve (as per the central limit theorem).

Wednesday, July 20, 2011

Continuing our discussion of siege weapons in the original Chainmail game (the last post concerning catapult fire), and keeping in mind how these mechanics formed the basis for fireball and lightning bolt and other spells and abilities. Today we'll look at the cannon rules.

Cover: Cannon fire into woods is not permitted. Far the effect of cannon fire on specific targets of wood or stone, see the section entitled SIEGES.

Method of Fire: Fire is in a straight line to a target specified by the player firing. (Exception is the Bombard, see the rule below.) A wooden dowel is placed at the muzzle of the cannon, and a 6" "variation measure" is placed at the other end of it (the target end). At this time the end must pass directly over, rest on, or point to the specified target. The center of the variation measure is placed at the far end of the firing dowel. The variation measure is marked off in 1½" segments and numbered from 1-6 as illustrated below:

A die is rolled by the player firing the cannon, and the end of the dowel is then moved to the number on the variation measure which corresponds to the number rolled on the die. This procedure represents the variation in cannon balls, irregular gun barrels, and windage. The Dowel: The length of a firing dowel will correspond to the maximum range of the cannon which it represents. Each is colored alternately white and black to represent the flight and bounces of a cannon ball. BEFORE PLACING THE DOWEL THE PLAYER FIRING MUST STATE WHETHER HE IS FIRING SHORT (white) OR LONG (black) AT THE TARGET. All figures that are touched by the named color on the dowell [sic] are eliminated. The color sections of the dowel, reading from muzzle to roll, are:

Any terrain features which interpose with ANY section of the dowel stop the flight of the cannon ball at that paint. These terrain features include high ground, barricades made of substantial material (wood planks or stone), trees, etc. Objects the height of a man will stop the flight of the cannon ball if they are substantial and fall within the color section named for hits. A body of water will likewise stop the flight of the cannon ball if it is passed over by a section of the dowel colored the color named for hits, other than the first such colored section which represents the cannon ball in level flight, not bouncing.

Bombards: Although the size and weight of a Bombard is such that the usefulness is restricted to sieges, occassional [sic] inclusion of a Bombard might add something to your wargame. The Bombard can be fired as either a Cannon or indirectly as if it were a Catapult. If it is fired indirect a triangulation must be made just as if it were a Catapult, and in addition the variation measure is used when the line of flight is generally determined. There is no flight-bounce-roll, for the Bombard fires an explosive shell. Use a 3½" diameter circle "hit area" marker when the place the shell hits is finally determined.

Example of Firing: A player decides to fire a Heavy Field Gun at the exact center of an advancing enemy pike square. The target is close, so the player elects to call WHITE. He places the dowel, lays the variation measure at its end, and rolls the die. The number rolled is 4, so the shot goes straight. The target is 26" distant and 8" deep, so the full 3" of the second white section, and the full 1" of the third section, fall upon it. All figures touched by the white sections of the dowel (including figures not named as the target -- even friendly troops) are removed as casualties. [CM, p. 13-14]

Got all that? So basically a cannon is fired at a certain target unit (unlike catapults in which you declare (x, y) distances in inches for the shot), and you're tracking the bounce of a cannonball, creating certain "fields" where death is caused (2-3 fields decreasing from 16" to 1" in length). There is always a variation die in this play, with 3-4 indicating on target, or otherwise moving the fields a few inches short or long (as opposed to catapult fire, for which variation is optional). Again, any target figure the fields touch is eliminated (note: cannons are not mentioned in the Fantasy Supplement, and thus no fantasy types are given any immunity to that effect).

Note a possibly important distinction between catapults and cannons: the former are Indirect fire (i.e., can be arced up over obstacles), while the latter are not (explicitly blocked by high ground, strong barricades, and trees). If these rules were applied the same way to fireballs and lightning bolts (respectively), then we would have some interesting repercussions, especially in the underground setting. Other questions and comments, as before:

First: Is this 1:1 or 1:20 scale for the cannons? As we saw for catapults, there are several compelling reasons why this whole section might be considered "misplaced", and that it would fit better in the Siege section, which is at man-to-man (1:1) scale. Again we can look at the singular language involved ("bounces of a cannon ball"), and the irrationality of having a battery of 20 cannons with assumed "variation in cannon balls, irregular gun barrels", etc., all firing and bouncing at exactly the same distance. Even though you've got language for Bombards specially restricting those to sieges, I think the whole section would be better understood if moved to the Siege/Man-to-Man section.

Secondly: Is the area of effect reasonable? Take the white hit area for the light field gun, a total of 19" long. This is some 19/0.5625 = 33.8 standard figures deep (if at 1:20 scale, killing 676 men). Or double that if you allow the listed width (5/8") to contact 2 figures on each side (over 1200 men?) And this from apparently one single cannonball. Or think of it this way (again at 1:20 scale): the standard figure presents a front scale 22.5 feet across (3/4 inch/fig × 10 yards/inch × 3 feet/yard); I like to think of that as about 7 men across in formation; and yet the single cannonball kills every man across this field over 20-feet wide. I don't think that's reasonable.

Thirdly: Is the method of fire reasonable? Catapults are entirely based on player skill (with its distance-declaration mechanic), but cannons have a much simpler targeting mechanic to apply (declare an enemy unit, instead of a location). This is probably more like what we're familiar with in D&D itself. There's mandatory range variation (2/3 chance to modify by 1.5 or 3"), although it is less than the catapult optional rule (up to 6" in either direction). I think that's pretty reasonable, pardoning the expectation for bouncing cannonballs and the need for several specially-marked dowels. (Caution: I haven't ever playtested this.)

One other thing that catches my eye: the "Example of Firing" indicates a target that by my standards would be a huge unit! "An advancing enemy pike square... 8" deep". So if that's literally a square 8" on a side, that's 8/(3/4) = 10.67 normal man-sized figures, or something like 100 to 120 miniatures on the table just for that unit (2,000 to 2,400 individual men?). Maybe I'm playing with Lilliputian-sized units in my wargaming, but that seems really enormous. Although if that actually was the standard at the time, then it would at least partly mitigate the difficulty of directing range declarations onto a given target for catapult fire, etc. (as mentioned last time). See also Swords & Spells, which specifies some large minimum figure counts for certain formations ("Mass means a formation of troops at least 15 figures across and six ranks deep... Column Mass is a formation at least ten figures across and eight ranks deep..." [S&S, p. 6]).

Monday, July 18, 2011

The original Chainmail rules seem pretty well-thought out in many regards: scales for time, ranged weapons, movement, space taken up by figures and personnel are all pretty accurate according to my research and calculations.

One place that seems not-so-realistic are siege weapons: catapults and cannons. Although siege weapons are by definition meant to be used in a siege (attack on a static fortification), in Chainmail these weapons appear in the basic, mass-scale, open combat section (p. 12-14). I'm very skeptical that weapons such as these were used or usable against units of mobile men in the open field (I can't find any research backing up such use), and I'm likewise skeptical of the timing, range, and effect of these weapons in Chainmail. It seems much more "gamey" and unrealistic than the rest of the rules -- and this is important because, after all, the rules to magic attacks such as fireball and lightning bolt were based on these mechanics (and more generally, the D&D spell system as a whole, plus giant rock-throwing). Today we'll look at the catapults.

For the Hit Area cut a circular plastic disc to the diameter stated above. All figures wholly or partially under the circular Hit Area are killed. (For the effect of catapult hits on other artillery pieces, structures, etc., see the section entitled SIEGES.)

Rate of Fire: Light Catapults fire every other turn, and Heavy Catapults every third turn, provided they ore fully crewed and have not been moved during the previous two or three turns, as the case may be. Full crew and reduction in rate of fire for partial crews are shown below:

Method of Fire: The player firing a catapult must call the range by stating the distance (in inches) he is firing and how far left or right the missile is to fall (subject to the 45 deg. arc of fire limitation). A triangulation is then made, with the missile falling along the long side of the triangle at the number of inches called.

Fire Optional: Roll two different colored dice. One color is for an overshoot and the other is for an under-shoot. To decide which number of use you take the higher of the two. Miss is in inches, shown by dice spots. If they tie then the rock lands at the specified range. This method is simple but effective. [Chainmail, p. 12-13]

Now, here are some questions and observations brought up by this rule section.

First of all, how many catapults and crew are being talked about here? Recall that the Chainmail mass-combat rules are at a base of 1:20, i.e., one figure represents 20 men. So are we talking about one catapult at a time, or 20? Is the "crew" mentioned 4 men, or 4 figures (80 men)? An important clue: this section predominantly uses the singular, i.e., "firing a catapult", "the missile", "the rock lands at the specified range". Also, if there were multiple catapults, then reduced crew (perhaps all crew for some of the catapults) should result in reduced strength of fire (at the same rate), not reduced rate of fire. My theory is that this section would make more sense if it was moved to the "Siege" section later on, which is written in terms of singular man-to-man action.

(Aside on the Siege section p. 22-24: Note phrases like "One man carrying a ladder moves at one-half speed..." I think this is best interpreted as an individual man -- hard to see how 20 men or more are required to carry a ladder, etc. Argument against this would be that the Man-to-Man Combat section doesn't start until the following page [p. 25]. Argument again in favor of this is that Gygax largely copy-and-pasted the whole Siege section into D&D's Swords and Spells, except for seeing a need to update these passages from "men" to "figures", e.g., "One figure representing ten first-level creatures is able to carry a ladder at one-half normal speed...", [Swords & Spells p. 23]. Edit: And as pointed out by UWS Guy, the Chainmail Siege rules do in fact explicitly say that "it is suggested they be used in combination with the rules for man-to-man combat" which come later [CM p. 22].)

Secondly, is the area and effect of a catapult hit reasonable? Does a single "rock" possibly effect a 2" or 3½" diameter area (keeping in mind that later on, giant rocks will act as the former, and fireballs as the latter)? Assuming that figures for normal men are on bases 3/4" (25mm) square, then they take up an area (3/4)^2 = 0.5625 square inches. Note that a light catapult affects an area of pi = 3.14 square inches = scale 314 square yards (1"=10 yards) = 5.58 figures = 100 men or more (note rule phrasing "all figures wholly or partially under the circular Hit Area are killed"). A heavy catapult affects an area 9.62 square inches = 17.1 figures = 340 or more men. From one single rock? Highly unlikely! So perhaps that's more argument back for a whole battery of catapults firing in unison, although I don't think that such a thing every actually existed, especially in the open field (and see more below).

Thirdly, is the "Method of Fire", declaring the specific range of the shot prior to measuring (based purely on player distance-estimation skill), a reasonable game mechanic? I recommend that you test this out yourself, because I did recently, and prior to that I hadn't realized how incredibly friggin' hard this was. It's one thing to estimate whether an enemy is inside a 12" charge limit or a 24" maximum crossbow shot (that being a reasonable skill and "fog of war" simulator, I find) -- but calling the exact pinpoint distance of something on the tabletop between 1 and 4 feet away, in two axes, is something entirely different. It's practically impossible!

(Aside: And I'm not even talking about use of the "Fire Optional" rule for range variation. I think there's a serious typo in that section: the phrase "higher of the two" indicates that the most probable result is to shoot 6" short or long, with decreasing probability the closer you get to your target. If the phrase were "lower of the two" then you get a more-reasonable triangular probability distribution sloping away from the target point -- Equivalent to: roll 2d6, for every point below 7 your shot is that many inches short, for every point above 7 it's that far long. Note also that giants function precisely as light catapult rules, referenced here via both Chainmail and Original D&D, so presumably this optional rule is available for them. In fact, that's explicitly re-stated in the Holmes blue-book D&D rules for giants, right down to including what I think is the terrible typo regarding "take the greater" die [Holmes p. 26]. And can this be used for fireball attacks? I guess that's your call.)

But throw out realism considerations, and perhaps these last two dilemmas resolve each other. It might be reasonable gameplay to have catapults given a nearly impossible-to-target mechanic based on player skill (neglecting optional rule above), but counteract that with an unrealistically huge area of effect, in the hope that if you get anywhere near the target, one or more figures may be knocked off by it. Does that make sense? I think probably so. If the catapult/cannon section were snipped out of the Chainmail basic rules and moved to the Siege section, then I think basic Chainmail is a very good simulation, and those siege weapons are a more playful toy-like add-on; and at man-to-man scale, like Sieges and all of the rest of the end of the book. It doesn't seem like killing hundreds of men per shot in the open field is something that real-life catapults were prone to do. Unfortunately, however, much of these mechanics were "baked in" and carried forward as legacy material into several editions of D&D and AD&D (with occasional apologetic caveats: see Gygax in AD&D DMG p. 109, last paragraph).

One final note: While the basic Chainmail rule says that "All figures wholly or partially under the circular Hit Area are killed", this is again only in the context of normal men in the historical section. The rule is modified in the Fantasy Supplement at the end, such that catapults (and giant throwing) only effect the lower-end types such as "Halflings, Sprites, Dwarves... Orcs, Heroes... Ogres, Treants, and Rocs" (up to about 6 hits or so). This excludes the more powerful creatures such as opposing Trolls, Giants, Super-Heroes, Wizards, Dragons, and Elementals.

(P.S. You may have noticed that I took a month off from posting, just because I've been busy. All good stuff: teaching double-length accelerated stats courses every night in the college's summer module; playing lots of Book of War as both playtests and my new favorite pastime. We'll see how regular I am through the rest of the summer.)